International Business Machines Corporation

Other

Howard L Kalter

Claude Louis Bertin

William R Tonti

John Atkinson Fifield

Wayne John Howell

Jeffrey John Welser

H Bernhard Pogge

Jack Allan Mandelman

Anthony Richard Bonaccio

Erik L Hedberg

Jeffrey H Dreibelbis

Gordon A Kelley, Jr

John Edward Cronin

John Edward Barth, Jr

Johann Greschner

Chin-Long Chen

Donald Lawrence Wheater

David V Horak

Chung H Lam

Steven J Holmes

Toshiharu Furukawa

Wayne Frederick Ellis

Hussein Ibrahim Hanafi

Douglas Craig Bossen

Waldemar Walter Kocon

John E Barth

Robert M Blake

Willem B Van Der Hoeven

Edward J Nowak

Donald M Kenney

Thomas M Maffitt

Scott C Lewis

Hsing-San Lee

Albert Stephan Bergendahl

Stuart Mcallister Burns, Jr

Charles E Drake

Mark Charles Hakey

Paul A Farrar

William Paul Hovis

Christopher P Miller

Sandip Tiwari

Paul A Rabidoux

Anthony M Palagonia

Francis Roger White

Bijan Davari

Bernadette Ann Pierson

Dennis A Schmidt

Patricia E Marmillion

Anatol Furman

Raymond J Rosner

Daniel J Nickel

George S Prokop

James A Yankosky

Minh H Tong

David Meltzer

Thomas James Heller, Jr

Dale E Pontius

Tin-Chee Lo

Kenneth E Beilstein, Jr

Gary Douglas Grise

Harish N Kotecha

Parsotam Trikam Patel

Robert Dean Adams

Michael Ignatowski

Roy Childs Flaker

Xiaowei Tian

Francis W Wiedman, Iii

Kenneth S Gray

Yotaro Mori

Gordon Arthur Kelley

Ning Hsieh

Sridhar Divakaruni

Rex Ngo Kho

Charles H Stapper

Johann Werner Nagel

Donald B Kiley

Steven Platt

John Stuart Parenteau, Jr

Stuart McAllister Burns, Jr

Steven W Thomashot

Large area chip functionality is tested at an intermediate level in the manufacturing process. A process sequence is implemented in which a layer of insulator material is deposited over the chip. This layer is then processed to selectively open areas over existing vias which are to be used for chip level testing. The other vias remain covered with insulator. A sacrificial metal level is then deposited on the insulator layer and patterned to create adequately large test pad areas connected to exposed vias. This metal layer and the insulator layer covering the other buried vias are removed after testing to re-establish the full via set. As an extension to this basic test process, test circuits can be formed around or beside the chip to be tested in the kerf areas separating the chip from other chips on the semiconductor wafer. Connections to the test circuits is with a sacrificial metal layer over an insulator layer. The sacrificial metal layer and insulator layer are removed after testing. The test circuits are scribed off in the process of separating the chips after back end of line processing is completed.

Method for chip testing

A densely packed array of vertical semiconductor devices having pillars and methods of making thereof are disclosed. The array has rows of wordlines and columns of bitlines. The array has vertical pillars, each having two wordlines, one active and the other passing for each, cell. Two wordlines are formed per pillar on opposite pillar sidewalls which are along the row direction. The threshold voltage of the pillar device is raised on the side of the pillar touching the passing wordline, thereby permanently shutting off the pillar device during the cell operation and isolating the pillar from the voltage variations on the passing wordline. The isolated wordlines allow individual cells to be addressed and written via direct tunneling, in both volatile and non-volatile memory cell configurations. For Gbit DRAM application, stack or trench capacitors may be formed on the pillars, or in trenches surrounding the pillars, respectively.

Structure for folded architecture pillar memory cell

A multi-level memory cell capable of storing two or three bits of digital data occupies only four lithographic squares and requires only one or two logic level voltage sources, respectively. High noise immunity derives from integration of the multi-level signal in the memory cell directly from logic level digital signals applied to two capacitors (as well as the bit line for the eight level mode of operation) by using capacitors having different values in order to avoid digital-to-analog conversion during writing. The capacitors can be simultaneously written and read to reduce memory cycle time. Transistor channels and capacitor connections are formed on adjacent semiconductor pillars using plugs of semiconductor material between pillars as common gate structures and connections. Opposite surfaces of the pillars also serve as storage nodes with common capacitor plates formed by conformal deposition between rows of plugs and pillars.

Multi-level dram trench store utilizing two capacitors and two plates

Wafer test and burn-in is accomplished with state machine or programmable test engines located on the wafer being tested. Each test engine requires less than 10 connections and each test engine can be connected to a plurality of chips, such as a row or a column of chips on the wafer. Thus, the number of pads of the wafer that must be connected for test is substantially reduced while a large degree of parallel testing is still provided. The test engines also permit on-wafer allocation of redundancy in parallel so that failing chips can be repaired after burn-in is complete. In addition, the programmable test engines can have their code altered so test programs can be modified to account for new information after the wafer has been fabricated. The test engines are used during burn-in to provide high frequency write signals to DRAM arrays that provide a higher effective voltage to the arrays, lowering the time required for burn-in. Connections to the wafer and between test engines and chips are provided along a membrane attached to the wafer. Membrane connectors can be formed or opened after the membrane is connected to the wafer so shorted chips can be disconnected. Preferably the membrane remains on the wafer after test, burn-in and dicing to provide a chip scale package. Thus, the very high cost of TCE matched materials, such as glass ceramic contactors, for wafer burn-in is avoided while providing benefit beyond test and burn-in for packaging.

Structures for wafer level test and burn-in

A semiconductor structure having a substrate, an insulator above a portion of the substrate, a conductor above the insulator; and at least two contact regions in the substrate on opposite sides of the portion of the substrate, wherein a voltage between the contact regions modulates a capacitance of the conductor.

Voltage controlled transmission line with real-time adaptive control

The disclosed invention provides a reduction of voltage noise or bounce in logic chips and does so in a practical way without requiting additional circuit elements that impact on circuit performance or speed. Broadly this reduction in voltage bounce is achieved by forcing the unused Input/Output (I/O) circuits, i.e., those chips not being activated, to serve as alterative paths to the voltage power supply used by the switching circuits. More particularly this is accomplished this by grouping the I/O points on the chips into logical, functional units such as data buses, control lines, the I/O points on switched circuits, i.e., those switched at high frequency and the I/O points on static circuits, i.e., non-switched and interconnecting and using the I/O points on the static circuits and the power supply drives coupled thereto as alternate pats to the power supply used by the switched circuits. In this way the inductance in the switched power supplies can be substantially reduced such that voltage bounce in the circuit is substantially reduced without adversely impacting on circuit speed.

Interconnected integrated circuits having reduced inductance during switching and a method of interconnecting such circuits

A densely packed array of vertical semiconductor devices, having pillars, deep trench capacitors, vertical transistors, and methods of making thereof are disclosed. The pillars act as transistor channels, and may be formed utilizing the application of hybrid resist over a block of semiconductor material. Drain doped regions are formed on the top of each pillar. The source doped regions and the plate doped regions are self-aligned and are created by diffusion in the trenches surrounding the pillars. The array has columns of bitlines and rows of wordlines. The capacitors are formed by isolating n,polysilicon in trenches separating said pillars. The array is suitable for GBit DRAM applications because the deep trench capacitors do not increase array area. The array may have an open bitline architecture, where the plate region is common to all the storage nodes or a folded architecture with two wordlines that pass through each cell having stacked transistors, where one wordline is active and the other is passing for each cell.

Method of forming self-isolated and self-aligned 4F-square vertical FET-trench DRAM cells

A self-terminating module is provided that at least partially terminates a signal line when the self-terminating module is coupled thereto. The self-terminating module comprises an internal non-self-terminating module directly coupled to an internal termination circuit. Preferably an active internal termination circuit is employed. A pass circuit may be coupled between the internal termination circuit and the internal non-self-terminating module so as to pass a received signal therebetween with fewer reflected signal contributions. When a pass circuit is employed, a delay circuit responsive to a trigger signal controls signal transfer between the internal termination circuit and the internal non-self-terminating module. One or more self-terminating modules may be coupled to a signal line and the termination impedance of each module is selected to provide adequate signal line termination without significantly loading the signal line when one or more of the self-terminating modules are coupled thereto.

Method and apparatus for providing self-terminating signal lines

Multi-level DRAM trench store utilizing two capacitors and two plates

An assembly is provided that includes an interposer having first and second substantially flat, opposed surfaces, and at least one speed critical signal line extending directly through the interposer from the first surface to the second surface. A first IC is coupled to the first surface of the interposer and has a first external connection mechanism coupled to the at least one speed critical signal line. A second IC is coupled to the second surface of the interposer and has a first external connection mechanism coupled to the at least one speed critical signal line. Preferably at least one non-speed critical signal line is provided within the interposer and is coupled to a second external connection mechanism of the first IC and/or the second IC for delivering non-speed critical signals thereto or for receiving such signals therefrom. A chip carrier having a cavity formed therein also may be provided wherein the second surface of the interposer is coupled to the chip carrier and the second IC is disposed within the cavity. One or more carrier signal lines may be provided within the chip carrier and coupled between the interposer and the second IC. The first and/or the second IC also may comprise control logic adapted to select a number of drivers within either IC that drive a particular signal line.

Method and apparatus for increasing interchip communications rates

An off-chip driver circuit including an enhancement PFET, a depletion PFET, a depletion NFET and an enhancement NFET connected in series. The large enhancement PFET and large enhancement NFET turn off the OCD in tri-state and to turn off the unused half of the OCD to prevent overlap current when driving a '0' or a '1'. A first gate signal is applied to the gate of the enhancement PFET and a second gate signal is applied to the enhancement NFET. A fixed voltage is connected to the gate of the depletion NFET and ground to gate of the depletion PFET. An output signal is obtained from a node between the depletion PFET and depletion NFET devices. In another embodiment, a reflection/overshoot sensor 60 is added. The output of sensor is connected to the body of a depletion PFET and an NFET. The feedback from sensor is such that the threshold voltage of the depletion devices are made more positive if the sensor detects that the output is being over-driven. A more positive threshold voltage will reduce the driver's IDS, but leaves the device in the linear mode.

Complementary depletion switch body stack off-chip driver

A first, &ldquo;known good&rdquo; reference off-chip driver circuit actuated by an initial logic program (IPL) input signal has an output lead connected as one of the inputs to a comparator circuit for providing a reference off-chip driver output signal. A second off-chip driver circuit including a plurality of &ldquo;n&rdquo; separate driver circuit paths connected to input signal and produces output signals connected to a common node to provide output driver signals to the common node. The common node is connected to the second input of the comparator circuit for comparison with the reference off-chip driver output signal from the first off-chip driver circuit to determine the operating state of the second off-chip driver circuit with respect to the operating state of the first off-chip driver circuit.

Redundant input/output driver circuit

A densely packed array of vertical semiconductor devices, having pillars, deep trench capacitors, vertical transistors, and methods of making thereof are disclosed. The pillars act as transistor channels, and may be formed utilizing the application of hybrid resist over a block of semiconductor material. Drain doped regions are formed on the top of each pillar. The source doped regions and the plate doped regions are self-aligned and are created by diffusion in the trenches surrounding the pillars. The array has columns of bitlines and rows of wordlines. The capacitors are formed by isolating n.sup.+ polysilicon in trenches separating said pillars. The array is suitable for GBit DRAM applications because the deep trench capacitors do not increase array area. The array may have an open bitline architecture, where the plate region is common to all the storage nodes or a folded architecture with two wordlines that pass through each cell having stacked transistors, where one wordline is active and the other is passing for each cell.

Self-isolated and self-aligned 4F-square vertical fet-trench dram cells

A densely packed array of vertical semiconductor devices having pillars and methods of making thereof are disclosed. The array has rows of wordlines and columns of bitlines. The array has vertical pillars, each having two wordlines, one active and the other passing for each cell. Two wordlines are formed per pillar on opposite pillar sidewalls which are along the row direction. The threshold voltage of the pillar device is raised on the side of the pillar touching the passing wordline, thereby permanently shutting off the pillar device during the cell operation and isolating the pillar from the voltage variations on the passing wordline. The isolated wordlines allow individual cells to be addressed and written via direct tunneling, in both volatile and non-volatile memory cell configurations. For Gbit DRAM application, stack or trench capacitors may be formed on the pillars, or in trenches surrounding the pillars, respectively.

Growing community of inventors

Colchester, VT, United States of America

Howard L Kalter